#include "Base64.h"
#include <iostream>

static const std::string base64_chars = 
             "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
             "abcdefghijklmnopqrstuvwxyz"
             "0123456789+/";


static inline bool is_base64(unsigned char c) {
	return (isalnum(c) || (c == '+') || (c == '/'));
}

std::string base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len) {
	std::string ret;
  	int i = 0;
  	int j = 0;
  	unsigned char char_array_3[3];
  	unsigned char char_array_4[4];

  	while (in_len--) {
    	char_array_3[i++] = *(bytes_to_encode++);
    	if (i == 3) {
      		char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
      		char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
      		char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
      		char_array_4[3] = char_array_3[2] & 0x3f;

      		for(i = 0; (i <4) ; i++)
        		ret += base64_chars[char_array_4[i]];
      		i = 0;
    	}
  	}

  	if (i)
  	{
    	for(j = i; j < 3; j++)
      		char_array_3[j] = '\0';

    	char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
    	char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
    	char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
    	char_array_4[3] = char_array_3[2] & 0x3f;

    	for (j = 0; (j < i + 1); j++)
      	ret += base64_chars[char_array_4[j]];

    	while((i++ < 3))
      	ret += '=';

  	}

  	return ret;
}

std::string base64_decode(std::string const& encoded_string) {
  	int in_len = encoded_string.size();
  	int i = 0;
  	int j = 0;
  	int in_ = 0;
  	unsigned char char_array_4[4], char_array_3[3];
  	std::string ret;

  	while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
    	char_array_4[i++] = encoded_string[in_]; in_++;
    	if (i ==4) {
      		for (i = 0; i <4; i++)
        		char_array_4[i] = base64_chars.find(char_array_4[i]);

      		char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
      		char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
      		char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

      		for (i = 0; (i < 3); i++)
        		ret += char_array_3[i];
      		i = 0;
    	}
  	}

  	if (i) {
    	for (j = i; j <4; j++)
      		char_array_4[j] = 0;

    	for (j = 0; j <4; j++)
      		char_array_4[j] = base64_chars.find(char_array_4[j]);

    	char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
    	char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
    	char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

    	for (j = 0; (j < i - 1); j++) 
			ret += char_array_3[j];
  	}

  	return ret;
}

